Sewage disposal system



March 21, 1939.

W. S. BOWEN SEWAGE DISPOSAL SYSTEM Filed Feb. 5, 1955 3 Sheets- Sheet l 3 Sheets-Sheet 2 W. S. BOWEN sEwAGE DISPOSAL SYSTEM Filed Feb. 5, 1935 Mrch 21,1939.

lll

n March 21,1939; n w s, BOWEN 2,151,079

SEWAGE DISPOSAL SYSTEM Filed Feb. 5, 1955 3 Sheets-Shea?l 3 ffii' 56 D Z9 t: 56

INVENTOR. iii/[iam Sjyvencer0wen,

WW1 MIM@ rincantati Mu. z1, 193e 4'UNITED STATES PATENT? oFFicE 6 Claims.

'Ihe .presentinvention relates to sewage'dis-` posal systems and embodies, more specifically, an improved system by means of which raw sewage may lbe received, without any preliminary treatment, and treated in such fashion as to form waste Aeiliuient of a non-objectionable nature and other end products which may be either conveniently disposed of or utilized as commercial products or as products by means of which the treating process may be carried out. n

Ordinarily, f about` half the solids in sewage are organic materials. It is these materials that give rise to diillculty in sewage disposal and many existing processes and systems treat such materials bacteriologically. Such treatment is effected by settling and digestion of the solids in large tanks, filter beds, drying beds, Imhoi tanks, sprinkling filters. activated slu'dge tanks, and vacuum filters.' In most of these systems chlorine, or other deodorants, are used in` various forms.

' Moreover, chemical coagulants of variousv types are added to aid in the removal of the suspended and colloidal solids; f In this connection, extensive use is made of aerobic bacteria to consume the organic solids, and by slow oxidation, to change them to non-objectionable forms. However, after these various steps have taken place, the residue still must be disposed of. This residue consists of clear effluent containing soluble solids and about eighty per cent. dry filter cake of low grade fertilizerquality. Methane is produced in the Imhoff tanks and digesters.y These existing steps require large and expensive equipment that cannot be located in the centers of population and therefore necessitate long and expensiver sewer lines.

The present invention approches the problem Y of sewage disposal in both a chemical and mechanical fashion and does not require the use of biological and slow speed processes. In-general, the sewage is mechanically treated to separate, eilectively, the eilluent from the solids and the solids are further treated to either dispose f' chanical treatment possible andenable end prodl of them in an entirelyeillcient and satisfactory fashion, utilizing the heat content thereof in the carrying out of the process. or else treating them in such fashion as to render them commercially salable. `In addition to the foregoing mechanical'treatment, the sewage is treated chemiA cally 'in an effective fashion to render the melucts of desired characteristics to be obtained.

` At this point it is to be noted that the invention is not limited specifically to the ltreatment of sewage. but may be highly useful in the dis'- position of garbage or other waste products, the adaptation ofthe invention thereto being obvious to one skilled in the art.

[The primary end products resulting from the process of the present invention include one or l more exhausts of deodorized air and vapor to the atmosphere, condensate, electric power, and chilled and powdered slag or ash. In this connection, it is to be noted that the B. t. u. content of the organic matter is from 7500 to 15,000 10 B. t. u. per pound of solid and is ample to carry out the process as outlined, with some surplus power available for the manufacture of electrolytic chlorine and sodium hydroxide from sodium chloride solution.

An object of the present invention, accordingly, is to provide a sewage disposal system by means of which raw sewage may be rapidly and effectively treated to form end products of non-objectionable nature which may be readily disposed of, and also products which are commercially salable.

A further object of the invention is to provide a sewage disposal system of the above character wherein the sewage is subjected to a purely chemical and mechanical treatment, the process being of such nature as to avoid the necessity of using large and expensive equipment.

A further object of the invention 'is to provide a method and apparatus for treating sewage and other waste products in such fashionas to form end products of commercially salable character as well4 as of a non-objectionable nature.

Further objects of the invention will be apparent as it is described in connection with the accompanying drawings, wherein Figure 1 is a combined schematic representation of an apparatus by means of which the present invention is carried out, as well as a flow diagram illustrating the process of the present invention;

Figure 2 is a view in section, taken on a plane -passing through the axis of a spray head constructed in accordance with the present invention and adapted particularly for use in connection with systems of the character described herein. This view is taken on the line 2-2 of Figure 4 and looking in the direction of the arrows;

Figure 3 is a view in side elevation, showing the device oi Figure 2;

Figure 4 is a plan view, partly broken away, to show details of the structure, and showing the device of Figure 2;

Figure 5 is a plan view of a slagging type furslagging type furnace of Figure and also showing the cooling mechanism used in connection therewith. 0

With reference to Figure l, sewage is introi duced into the system at I3 and directed into a screen pulper I I, which may consist of a cylindrical horizontal screen with a rotating rinternal paddle that is helical in shape, the paddle wiping the interior of the screen and forcing all light material therethrough while directing all lumps and other material out at a suitable outlet. This mechanism serves to roughly separate the sewage from solid materials which are not suitable for treatment in accordance with the present invention, these materials being disposed of in any suitable lfashion. For example, such materials may be introduced into a pulverizing or other mill and, after being pulverized, may be returned to the sewage disposal system at a suitable point.

The screened sewage is then directed through a pipe I2 into a deodorizer I3 where it is treated with chlorine or other suitable deodorant. This device may take the form of a washer in which the sewage is sprayed into a chamber and subjected to the action of chlorine.

From the deodorizer I3, a pipe I4 directs the sewage to a coagulating chamber I5 where suitable -chemical coagulants are introduced into the sewage, a suilicient period of time being -allowed for the reaction to take place. One form of coagulant is ferric chloride (FeCla) although the specific coagulant used constitutes no part of the present invention.

The resulting mixture is then introduced into a centrifugal separator I1 through a pipe I6 where the solids in the sewage are continuously separated. Waste eiiluent is discharged from the separator through a pipe I3 while the sludge is directed into a continuous mixer through a pipe I3.

From the mixer 20, the sludge is directed through a pipe 2I to a spray head 22 by means of which it is introduced into a spray drying chamber 23. A fan 24 withdraws the dried particles and gas from the drying chamber and directs them through a pipe 25 to a dust collector 26. 'I'he solid particles from the dust collector are directed into a furnace 21, the details of which are illustrated in Figures 5 and 6.

In order that the invention may be more eiTectively carried out, the furnace 21 is preferably positioned above a cooling chamber 23 in order that a continuous flow of molten slag will pass by gravity into a spray mechanism 23 within the cooling chamber. A fan withdraws the medium from the cooling chamber and directs it through a pipe 3i to a dust collector 32 from which'the exhaust isdirected through a suitable outlet 33 and the chilled slag is collected through an outlet 34.

Waste heat from the furnace 21 is directed through a pipe 35 into a boiler 36, the steam from which is supplied through a pipe 31 to a turbo generator 38. This turbo generator supplies power to suitable mechanism 33 which may be utilized to drive the equipment used in the carrying out of the process as well as power to a plant for making electrolytic chlorine and sodium hydroxide.

After the waste heat from the furnace passes through the boiler 36, it passes, together with entrained fly ash, to the drying` chamber 231 through a pipe 4I and'is thus further utilized.

allume Returning to the centrifugal separator. a portion of the emuent is directed into a washer 42 where it takes up waste heat and dust from the dust collector 23 through a pipe 43, being partially concentrated. From the washer 42, the eiiiuent flows through a pipe 44 to a multiple evaporatlng effect consisting of a plurality of members 45 in series.' Exhaust from the washer 42 leaves through an outlet 46 while the concentrated substance is directed through a pipe 41 to the turbomixer 20 where it is recombined with the previously separated sludge. A portion of the liquid from the centrifugal separator is directed through a pipe 43 to a surface condenser 43 which may be of any standard type. A pipe 50 then carries the liquid to the multiple effect 45, the condensate being removed through an outlet 5I. A pipe l2 carries the exhaust steam from the final eifect 45 to the condenser 43 in order to maintain the desired vacuum lin the multiple effect. If desired, an outlet may be provided in pipe 50 to exhaust some of the steam leaving the condenser 4,3.y

It will be observed that the dust collected from the dust collector 26 is high'in organic solids which have not been destroyed by the previous steps to which it has been subjected. This dust isv conveyed to the specially -designed powdered fuel slagging type furnace 21 which is illustrated in further detail in Figures 5 and 6. In these blown at a rate greater than the rate of flame travel so that the flame cannot strike back. 'I'he four flames which are forined thus swing around the cylindrical furnace in a vortex and result in a very intense combustion. The slag passes out at the bottom of the chamber through an outlet and falls upon the rotating spray head 23. As a result, the molten slag is directed outwardly into the spray cooling chamber wherein nozzles 53 are provided to introduce a suitable cooling medium. The cooled slag may be collected by a scraper 51 at the bottom of the cooling chamber where it is collected and directed into the dust collector by the fan 30. Ihe foregoing mechanism may follow the design of apparatus presently available.

In further reference to the structure shown in Figure 6, the spray wheel 23 is preferably formed of a suitable metal such as molded bronze impregnated with graphite or some other material which is later burned out, leaving a porous substance. The wheel is then mounted on the end of a hollow motor shaft 58 through which water is directed under pressure. As the molten slag falls upon the top.surface of ther spray wheel 23, it will be prevented from touching and adhering to the wheel due to the instantaneous layer of steam formed, since the surface of the wheel would be constantly covered with moisture. As a result, the product would tend to form more quickly into large grains much like the spherical -condition of water ona very hot stove. Incidentally, this structure might be utilizedv satisfactorily in solidifying molten metals of various types and the shape of the wheel 23 mayv be o f any convenient form.

The spray head shown in Figures ,2, y3 and 4 includes a body 53 which may be mounted upon a suitable supporting wall 6I). The body is yand nozzle member.

formed with an inlet -6I through which substances vmay be introduced intov the head, a chamber 62 being formed within the body. A tube 63 is secured to the bottom of the body and is provided with a bushing 64 at the bottom thereof which is adapted to serve as a valve seat Within the body 62 and tube 63 is a valve stem 65, upon the lower end of which a spirally formed member 66 is secured. This spirally formed member may be located by a cap 61 which is secured in place by a nut 68.

The cap61 and bushing 64 are preferably formed with cooperating curved surfaces to provide an annular and adjustable nozzle through which the substance may be sprayed under pressure.

The stem 65 may be located by the spiral member 66 which may be received snugly within the lower end of the tube 63 and, at its upper end, the stem is additionally located by a plug 69 which is slidably received within the chamber 62 and preferably provided with labyrinth packing 10. The stem 65 is threadedly engaged with the plug Y 69 as shown at 1| and extends upwardly above the plug to receive-a'micrometer wheel 12. An indexing finger 13 is secured to the body 59 and Afacilitates the proper adjustment of the mechanism in an obvious fashion. Rotation of the wheel 12 thus moves the valve stem 65 axially withfrespect to the plug 69l and body 59 to'vary the outlet between the bushing 64 and the cap Proper adjustment of the cap with respect to the bushing 64 willcause the substance to be sprayed in a very thin state that almost instantly ruptures into a fine spray or mist surrounding the nozzle tip in a circular horizontal plane.

The plug 69 is formed of greater diameter than the nozzle ring or bushing 64 and the cap 61 so that the liquid pressure will tend to hold the cap 61 against the bushing 64. l In an advantageous form of the mechanism, the plug 69 is threaded with 25 -threads per inch,

right hand. The threaded portion of the valve stem 65 is received within 'this threaded portion of the plug 69 and may thus be adjusted upwardly and downwardly. vThe micrometer wheel 12, in the above device, is divided into equal divi sions and, thus, for each division of the micrometer wheel, e stem and nozzle cap is moved .001 inch. After a proper adjustment of the cap 61 is made, the valve stem'is locked in position by means of a nut 14 which is preferably threaded upon the valve stem.

`In order that the nozzle may be cleaned in the event of clogging, a flooding mechanism is provided comprising a' crank member 16 having a yoke-shaped arm 16 adapted to engage suitably formed recesses in the plug 69.. Another arm 11 of the crank 15 is formed with an eye 16 to which a suitable operating member 19 is secured. A spring 80 is connected to an eye 6|, formed in the body 59, and also connected to the eye 18 in order that the arm 11 may be urged toward the body 69. In this fashion, the yoke-shaped arm i 16 urges the plug 69 upwardly and maintains the nozzle is effected `by pulling on the link` 19 to 'move the cap-61 away from the bushing 64, thus cap 61 in its desired position. Flooding of the dislodging any, solid particles that may cause a vital part of the mechanism inasmuch as the nozzle functions equally well without such a member present. In such event, of course, care should be taken to space the valve stem properly from the tube 63 adjacent the bushing 64.

In the event that the invention is applied to the disposal of garbage, the elements would include a grinding, milling, or crushing operation such as a pulverizing or attrition mill in order that the garbage may be brought to a uniform i'lneness preparatory to spray drying.

From the foregoing, it will be observed that the present invention provides a process and apparatus by means of which sewage may be disposed of effectively, being treated in such fashion as to facilitate the disposal of .waste products in an unobjectionable manner and form other products which are commercially salable or which are adapted for use in connection with the operation of the system. In addition, the invention includes specic 'details of structure which have been described above and the invention is not to be limited save as defined in the appended claims.

I claim:

1. The process for the disposal of sewage and other `waste material comprising drying the material to convert it into a residue of small substantially dry particles, burning said particles under sufficiently high temperature conditions to forma molten slag residue, and simultaneously spraying and cooling said molten slag to produce a chilled residue of small particles.

2. The process for the disposal of sewage and other waste material comprising drying the material to convert it into a residue of small substantially dry particles, burning said residue to generate suicient heat to form a molten slag residue and simultaneously centrifugally spraying the slag in the presenceof a cooling medium to produce a solidied residue consisting of small particles of slag.

3. 'I'he process of the disposal of sewage and other waste material comprising drying the material to convert it into a residue of small substantially dry particles, burning said residue to generate suncient heat4 to form a molten slag residue, flowing the slagv into contact with a chilling liquid, subjecting the slag and liquid to centrifugal force to spray them into a cooling medium to produce a solidied residue consisting of small particles of slag. i

4. The process set forth in claim 2 wherein the waste material is reduced to small substantially dry particles by spraying in a current of gases heated by burning the sewage residue.

5. The process for the disposal of sewage comprising separating a major portion vof liquid from the sewage to form a sludge. concentrating the liquid, mixing rit with sludge and spray drying the mixture tov form a residue of nely divided particles.

6. The process for the disposal of sewage comprising centrifuging sewage to separate an effluent from solid matter, concentrating the effluent by evaporation, mixing the concentrated emuent with the solid matter and spraying the vmixture into a current of heated gas to produce a residue of finely divided particles.

. v WILLIAM SPENCER BOWEN. 

